Various means have been used in the prior art to cut continuously extruded single strands of propellant into equal lengths within close tolerances. Generally prior art cutting devices were based on an extrusion having a constant rate, or on the ability of sensing a variable rate of extrusion. In the first instance, since the rate of extrusion was rarely constant for prolonged periods of time, cutters operating on a constant extrusion rate basis were unsuccessful. In the latter case, when the attempt was made in the prior art to sense the changing rate of extrusion, problems were often encountered when the range of strand extrusion was higher than the cutter's capability of adapting to that range and thus a deficiency resulted in high grain length variability. In the past strands were also collected in batches from manually charged and operated presses. Strands collected in this fashion were often transported to other areas and then manually fed into rotating fan type cutters. This interrupted form of production is generally less efficient and does not lend itself to adaptation to a continuous automated production assembly line permitted by the present invention.